Cort is a 13-year-old boy living with his father and his pet dog, Catfish, on a houseboat in Carolina. His mother left the family home six months ago, and Cort resents her for this. Struggling to deal with the loss of the stable home and family life he enjoyed, he blames her for leaving and claims to never want to see her again. Part of his resentment is because of the effect of her departure upon Cort’s father, who is now distracted and not looking after himself or Cort, turning up late for work and hardly eating. Cort sees this as his mother’s fault, and he resents his father for trying to win her back. These changes isolate Cort, who finds that Catfish is the only one who makes him feel less lonely.

The upheaval in his private life also affects Cort’s relationship with the place he calls home. While he previously loved living on the river and learning about the swamp with his father, he begins to believe that this knowledge is useless. Making this worse is his father’s insistence that his life on the swamp led to Cort’s mother leaving. Therefore, Cort is worried about recreating the same issues with Liza, the neighbor he has begun to develop feelings for.